Hi folks! I have some problems I want to solve: I am building a little
boilerplate project for https://adventofcode.com/ and I’ve stumbled into some
problems in regards to dune exec, dune test and --watch:
Excuse my long thread but I felt it was better to write down everything I’ve tried. the project looks like this can can be found in the development branch here GitHub - p1xelHer0/advent-of-ocaml at development
.
├── \_build
├── \_opam
├── day_01..25 - self-contained library and executable
│ ├── dune
│ ├── input
│ ├── puzzle_01.ml - solution to AoC, contains inline tests
│ └── runner.ml - executable, calls the `run` function from `Puzzle_01`
├── lib
│ ├── dune
│ └── util.ml - library all other modules can use, can contain tests
├── aoc.opam
├── dune
└── dune-project
The idea here is that each day I, or some other user, would start a
dune exec ./day_01/runner.exe -w
and a
dune test ./day_01 -w
To get immediate feedback on the test of the example data and the output of the written program.
Now, this does not work since dune locks the _build directory.
This lock CAN be disabled with setting DUNE_CONFIG__GLOBAL_LOCK=disabled but
now the processes crash instead, so this does not work in my case.
My approach to this was to create an alias:
(rule
(alias 1)
(deps ./day_01/input)
(action
(progn
(run dune build ./day_01)
(run ./day_01/runner.exe))))
Now, using dune build @1 -w and achieve the same thing as dune exec ./day_01/runner.exe -w. (I’m not sure if it’s the EXACT same thing but you get
idea…).
Defining this as an alias allow us to use multiple aliases for the dune build
command:
dune build @1 @runtest -w
The issue now become that the runtest alias runs ALL the tests of the project,
not just the test for day_01. So if I user leaves Day 1 of Advent of Code
uncompleted and move on to day 2 they’d have to clean up the file before moving
on. That’s not good!
I have not been able to pass parameters to the runtest alias when using the
build command above. I was thinking something in the lines of:
dune build @1 @runtest ./day_01 -w. But that does not work, it still runs my
tests in ./day_02 and lib/util.ml.
Another idea I had was to expand my alias to include the tests in the alias
itself:
(rule
(alias 1)
(deps ./day_01/input)
(action
(progn
(run dune build ./day_01)
; This seems like the easiest most straightforward solution?
; But this does not seem to work, or any alternative for that matter, be it
; runtest, build @runtest etc
(run dune test ./day_01)
; An idea I had was to run the inline test directly:
(run ./day_01/.puzzle_01.inline-tests/inline_test_runner_puzzle_01.exe)
(run ./day_01/runner.exe))))
Now ppx_inline_test specificly mentions that you can’t run the test executable
directly. Doing this results in the following:
You are doing something unexpected with the tests. No tests have
been run. You should use the inline_tests_runner script to run
tests.
The README mentions this here: GitHub - janestreet/ppx_inline_test: Syntax extension for writing in-line tests in ocaml code
But the best I could get from the test executable was:
(run /day_01/.puzzle_01.inline-tests/inline_test_runner_puzzle_01.exe inline-test-runner Puzzle_01)
This prints nothing.
I can verify by passing the -show-counts option to the test:
0 tests ran, 0 test_modules ran
Maybe I am missing something here? There also seems to be an issue open in
regards to running a single test, not sure if related to this: running a single test · Issue #34 · janestreet/ppx_inline_test · GitHub
So in the end, dune build @1 @runtest -w is the closest I’ve gotten. But I
don’t feel like it’s good enough. I can do better. I would like the runtest
alias only run the tests in the day_01 folder.
Thank you so much for taking your time to read this! I realize now that I
should’ve asked for help much earlier but on the flip side I’ve learned a lot
about dune! Am I even approaching this problem from the right angle? 
2 posts - 2 participants